1. Field of the Invention
The apparatus of the present invention relates to "wellhead lubricators" a term of art used in the oil and gas industry to describe a tool that is normally mounted on the top of a wellhead or "Christmas Tree" (another term of art in the industry) to house a wireline tool while the shutoff and/or master valve of the wellhead assembly are either opened to lower tools into the well under pressure or closed to prevent accidental falling of the wireline tool into the well during "make-up" or withdrawal. The lubricator acts as a pressure housing to allow a straight opening to the downhole tubing or to house a wireline tool during well shut-in. More particularly, the lubricator of the present invention provides a diverter means for guiding a wireline tool housed in the lubricator into a lubricator extension wherein all necessary tool "make-up" or changing can be done.
2. Description of the Prior Art
Prior standard lubricators are generally of a straight tube configuration and must ordinarily be disconnected from the wellhead in order to extract the wireline tool therefrom or to insert or "make-up" a different wireline tool therein prior to running the wireline back "down hole." Such prior art devices are illustrated in the following U.S. patents:
U.S. Pat. No. 2,755,863 issued to H. N. Stansbury, et al; and U.S. Pat. No. 2,710,064 issued to F. N. Osmun.
This design of a lubricator requires several operators and extensive time and thus expense as the entire lubricator has to be uncoupled and removed from the wellhead on every running or "trip" of the wireline tool or for sequentially checking or changing wireline tools or adding additional wireline tools.
U.S. Pat. No. 3,924,686 issued to J. F. Arnold attempted to solve the aforementioned problems by adding to the lubricator housing a laterally extending portion having a second tool opening for passage of the wireline tool therethrough while the housing remained attached to the wellhead and a guide means for guiding the wireline tool to the second opening when the tool is to be removed from the housing. While this structure allows for both passing the wireline tool into and out of the well through the point of attachment to the wellhead and passing the wireline tool through the second opening by providing laterally extending portion (30) of lubricator housing (12) and thus a single enlarged housing (11) which allows the wireline tool to shift to the position of FIG. 2 under the force of the diverter arm (35), the wireline tool can shift from this preferred lateral position at an angle relative to the vertical position in laterally extending portion (30) to the vertical position when diverter arm (35) resumes the position of FIG. 1 thus recreating the undesirable vertical positioning of the wireline tool for potentially falling down hole with the only remedy being time-consuming and expensive "fishing" operations to retrieve the tool. Further, Arnold's diverter arm (35) is fully manually operable from the positions of FIG. 1 and FIG. 2 and does not automatically assume a position of blocking the wireline tool from falling downhole.
U.S. Pat. No. 4,252,149 issued to W. W. Dollison and discloses a tool diverter for guiding flowline tools into selected flowpaths. The diverter member (13) closes the main flow line to allow a tool string to move therethrough. Diverter member (13) is pivoted by rotation of operating shaft (14), one end of which has a square cross-section engaged in a blind opening (15) in the diverter member (13). Shaft (14) is slidable axially within opening (15).
3. Summary of the Invention
It is therefore an object of the apparatus of the present invention to provide a wellhead lubricator having a lubricator extension with a tool opening for passage of a wireline tool therethrough and out of the well at deck or floor level.
It is a further object of the present invention to provide a wellhead lubricator having a lubricator extension connected to but independent of the wellhead pipe string.
It is a further object of the present invention to provide a wellhead lubricator with means positioned under bias of spring action for guiding or diverting the wireline tool into the lubricator extension to prevent the tool from falling downhole.
It is a further object of the present invention to provide guide or diverter means with fluid pressure activated means for selectively positioning the diverter to pass the wireline tool in and out of the well through the point of attachment to the wellhead.
The apparatus of the present invention provides a wellhead lubricator having a housing for vertically extending attachment to a wellhead assembly and a wireline for supporting a wireline tool therein and passing the wireline tool in and out of the well through the point of attachment to the wellhead, a portion extending laterally from the housing and forming a chamber therewith, a portion extending longitudinally from the lateral extending portion and connected therewith and having an opening at its bottom for passage of the wireline tool therethrough, a cap with bleed valve for closing the opening, and a guide or diverter in the housing positioned under the bias of spring action for guiding the wireline tool into the longitudinally extending portion but movable under fluid pressure to a second position for guiding the wireline tool in and out of the well through the point of attachment to the wellhead.